PASSENGERS:(Comet 1) 36 in three classes(Comet 1A) 44 in three classes(Comet 2) 44 in three classes(Comet 3) 58 in three classes, 78 in two classes(Comet 4) 56 in three classes, 81 in two classes, 109 in one class(Comet 4B) 71 in three classes, 101 in two classes, 119 in one class(Comet 4C) 79 in three classes, 101 in two classes, 119 in one class

KNOWN VARIANTS:G-5-1 and G-5-2: Two prototypes originally equipped with single-wheel main landing gear, G-5-1 later modified with 4-wheel gear; prototypes also modifed to test drooped leading edges and rocket assisted takeoffsComet 1: First production model and first aircraft to initiate commercial jet passenger sevice, entire Comet fleet grounded following crash of five of these models leading to discovery of structural failure of the passenger cabin; 9 built (5 crashed)Comet 1A: Similar to Comet 1 but with increased fuel capacity and reinforced structure for greater takeoff weight; 10 built (3 crashed)Comet 1XB: Comet 1A aircraft modified with stronger structure and oval windows to correct problems with earlier models; 4 convertedComet 2X: Developmental aircraft converted from a Comet 1 airframe and used to test new engines and other features for Comet 2; 1 convertedComet 2: Enlarged model with stretched fuselage for increased passenger load and larger fuel capacity, ordered by commercial operators but never entered service because of Comet 1 crashes; 22 built but 5 scrapped, 3 put into storage, and remainder converted into following variants primarily used by the RAFComet C.2: Cargo transport converted from aborted Comet 2 airframes with reinforced fuselage and cabin floor, used by RAF; 8 convertedComet T.2: Crew trainers converted from aborted Comet 2 airframes for RAF; 2 convertedComet 2E: Comet 2 airframes modified with new engines and used to test equipment for Comet 4; 2 convertedComet 2R: Comet 2 airframes fitted with special electronics in an unpressurized fuselage, used by the RAF; 3 convertedComet 3: Developmental model with lengthened fuselage for more passengers and fuel but project cancelled following Comet 1 accidents, leter used as prototype for Comet 4B; 1 built and 10 others scrappedComet 4: First variant certified for passenger operations following Comet 1 disaster, similar to Comet 3; 28 builtComet 4A: Short range version of Comet 4 with lengthened fuselage and reduced wingspan, order from Capital Airlines cancelled and did not enter production; none builtComet 4B: Short range version of Comet 4 similar to Comet 4A but with even longer fuselage and new engine; 18 builtComet 4C: Final production model, combined lengthened fuselage of Comet 4B with wing of Comet 4 for greater passenger load over standard ranges; 23 builtComet C.4: Transport variant of Comet 4C used by RAF; 5 builtComet 5: Proposed new model to compete with DC-8 and Boeing 707, not builtNimrod: Maritime reconnaissance aircraft developed from basic Comet 4C airframe